In a nighttime chorus of insects, the easiest way to identify individual katydid and cricket species is by listening to their songs, according to one of the world’s leading authorities on the jumping insects.

“Without sound, we’d be in a pickle,” said Thomas Walker, an entomologist at the University of Florida in Gainesville.

Relying on morphology–body shape, structure, and color–to identify some katydids and crickets is next to impossible, he says.